If you (plan to) own shares of US companies, better think twice. According to this article:
Do you own more than US$60,000 in U.S. stocks? If the answer is YES, then you are technically liable to pay U.S. estate taxes of up to 40 percent on those assets upon death.
And it adds:
" .... this tax is a MAJOR issue for foreign buyers of U.S. real estate"
The implications could be horrendous, you could have bought the shares just a short while ago, you could even be sitting on a paper loss, still, there will be a 40% tax on anything above USD 60K.
I am not aware of any other country in the world with the same laws, luckily.
The US seems to have lost its way. Pity, but that is the way all large empires eventually go, and may be that is not such a bad thing after all.